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Jadis JA 30 Monoblocks Modified
by Mr. Constantino García

Mr. Constantino Garcia has applied ToplineAudio package to Jadis JA 30 monoblocks.


I am writing some feedback about my modifieds monoblocks - JADIS JA30 - from a North city of Spain. I am a Spanish economist, 46 years old. My favourite hobby has been  hi-end since 30 years ago. I have owned several different gears during many years. Since 1996, I am the proud owner of JADIS JA30 monoblocks. I truly like to listen to all types of music; Jazz, Blues, Classical, Opera and even Pop at certain times.

Now my system for Hi-End is UNIDISC 1.1 source  Sonic FRONTIERS LINE3 preamplifiers (12 tubes), JADIS JA30 monoblocks and AUDIO-PHYSIC VIRGO speakers with VIRTUAL DYNAMICS cables. I have an  AV system as well.

For the last ten years, I have been very happy with this sound and I did not think about upgrading (Only source and  cables had been changed ) but during 2006 I was lucky to meet a nice man in Istanbul whose name is Kerem . Initially,  I have gotten in touch with him about Virtual Dynamics cables. We had a  VD cables deal and afterwards we began to speak about the possibility of a top synergy to attain the most truthful sound.

One day he told me about his deep passion in the modification practice. He had been guiding certain manufacturers for his projects  to obtain components like  the virtuous, custom-made  German silver-gold caps,  NOS Japanese  resistors. We started to elaborate the possibility to improve the performance of  my monoblocks to a high level. I had agreed with him and I decided to change the wires, caps and resistors, and replace the solders in the critical areas, the way Kerem has instructed me.

For so many weeks, I was a desperate man because I had these component  to change it,  but my technician was too busy After some time my friendly technician had done it. A few weeks later my pair of 30 Watt mono´s arrived and I unpacked them carefully. I think my technician did a very good job so I  was very excited to hear my new monoblocks but Kerem warned me beforehand that  the amplifiers  would need a good time to burn-in.

I have finalised the set-up, and  plugged all the connections  immediately. I turned on the gear. I  began with a Shostakovich disc (Synphony Nº 8  Chicago S. Orchestra.Decca) and I felt the sound was much cleaner, and more detailed but in some frequencies, I was not too happy; I  somehow felt this non-burned harshness effect.

I knew the mono´s do require some break in , approximately 100 to 150 hours to sound their best but after about 140 hours, the change was on.  The sound changed and everything was exactly right and a frequency extension appeared.

As the break in period progressed, the bass output is scaled down in proportion, and became well integrated with the rest of the frequency spectrum. Simultaneously, the monoblocks  “opened up” and the transparency increased.

Before the modifications, tonally, the bottom end was hefted, grunt and I had to  associate my system with powerful subwoofers. Initially,  it seemed to me that  no monoblocks  can break the laws of physics and make speakers exceed their capabilities, but after the modification, my  Audio Physic Virgo speakers seemed to have more control bass output.

The truth is that mod changes in JA30 did it and the monoblocks do have a deeper,flatter response at sub harmonic levels. That power is matched by speed and finesse, not sloppy loose as before (the bass is detailed, lifelike and under control).
The midrange is extremely detailed, ‘supernatural’ and again made me realize that I am not just listening to say, a guitar, but a musician playing a guitar. I think only the very finest of components can convey this sense of humanity.

The upper frequencies are smooth and extended. There is not just much more to say here, it is fantastic. On the opening track of ¨Mi Buenos Aires Querido (Barenboim,Teldec)¨the intro is very difficult for any amplifier or speakers, It was very easy for my amplifier. It was the most natural sound I had heard in  this disc. With¨ Three Blind Mice Vol 1 the amplifier did the same. ‘Fantastic!’ I said.

It is the best sound I had ever heard.  Body and smoothness with a scandal transparency. There is not a single missing note. You can hear ALL. The dynamics of the amps are now superb. The best I know.

The overall tonal balance and transparency  of my new JADIS JA30 seemed to step aside and let the music flow nice,  naturally and gracefully. I am sure I have a new amplifier. JADIS JA30 were very good. During 10 years they produced a nice sound for my ears . They were supplied with 2Svetlana 6550-B and 1 Ei ECC83 and 1 Ei ECC82  each one. I changed this pre-tubes with NOS Mullard  and the Power tubes with Svetlana KT88. Afterwards  I changed  one more to 6550 and I loved it.

The JADIS JA30 modified with the custom-made caps for Kerem and the famous NOS Japanese resistors must have transformed my amps into totally new ones. Now I think I can not  live without the wonderful sound of my new JA30.

I want to thank Kerem Kucukaslan for the help and recommendations. Without Kerem this miracle would have never existed.

Thank you my friend.


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